Plastic pile protector and method of covering a pile with same

ABSTRACT

A device and method for covering pilings of piers and the like includes a plastic cover or sheet which is wrapped around the piling for protecting the piling against rot, weather and wear. The plastic sheet ends overlap as they wrap around the pile. The ends are sealed and secured by a heatable strip extending between the overlapped ends of the sheet and which forms a fused plastic seam between the overlapped ends as the sheet is held tightly about the pile. A strap and a bar which presses over the heatable strip is provided for temporarily cinching the plastic sheet tightly about the pile and holding it while the heat fusing occurs.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates generally to methods and apparatus for coveringand thereby protecting the pilings of piers, wharfs, or other structuresextending from a waterfront or free-standing in a body of water.

2. Description of the Prior Art

Piers, wharfs, quays and free standing structures utilized for thedocking of vessels or as platforms in the sea are commonly supported bywooden, concrete or metal piles which extend longitudinally fromimmediately underneath the pier platform, downwardly through the waterto the earth's surface therebelow. Immersion of the lower portion of apile in seawater and exposure of the remaining portion of a pile to aninhospitable sea environment substantially diminishes a pile's usefullife. Unprotected piles, in addition to being exposed to water and theelements, are susceptible to attack by marine organisms. Various worms,snails, bacteria and marine life act to destroy the integrity of wood orto corrode and destroy the metal. Further, the piles are often rammed byboat fenders, breaking the piles. Abrasion by shifting and washing sandis especially a problem for metal and concrete piles. Ultimately, thewood, concrete and metal are destroyed and the piling must be replaced.This is a very expensive and labor intensive process. Therefore, variousprotective measures have been employed to forstall the deterioration ofpiling.

Various devices and methods have been utilized in the past to protectpiles. One of the oldest methods of protecting piles is to soak woodenpiles with tar. However, the tar soon wears off. More recently,coverings such as zippered plastic covers, plastic covers connected bytongue and groove, plastic covers which are overlapped and spiked, andfiberglass or plastic flanged and bolted covers has been used on metal,concrete and wooden piles. These cover devices have also provenunsatisfactory. Most importantly, most pile coverings do not provide agood seal and do not prevent water, marine life and bacteria fromentering the wood. While tar and mastics have been applied beneath thecovers, the seawater and animal life still can penetrate the plasticcover. Ultimately, the wood, concrete and metal are penetrated anddestroyed because the cover has holes punched in it by spikes or gapsare present in the flanges or cover ends.

To illustrate, one protective covering and method employed in the priorart utilizes a fiberglass cover. The fiberglass cover employed by thissystem is an axially flanged fiberglass split-sleeve which is tightenedaround a pile by bolting the axial flange together. Prior toinstallation of the fiberglass cover, the pile is covered with a masticand then spirally wrapped with a coated paper to seal the surface of thepile. The fiberglass cover itself does not seal the pile surface sincethe pre-formed fiberglass will not conform to surface imperfections anddiameter changes which are present in all wooden piles, concrete pilesand corroded metal piles. More mastics and caulks are applied about thecover in an attempt to further seal the pile from the water. However,the mastics and caulks wear and wash away and water and animal lifeattacks the pile beneath the cover.

A variation of the above method substitutes a plastic flangedsplit-sleeve cover in place of the fiberglass cover. A flanged cover ofeither fiberglass or plastic material must be custom sized to theparticular metal or wooden pile to be covered or else the fit isparticularly bad. Many piles are formed from tree trunks which arelarger at one end causing even a custom sized cover to fit poorly. Anadditional problem with flanged covers is corrosion of the flangedconnectors, which are usually nuts and bolts.

In addition to the naturally induced deterioration mentioned above, pilecoverings are also damaged by vessels striking or abrading their sidesduring docking. This is especially true of fiberglass covers which areinherently brittle and subject to cracking upon impact. Althoughfiberglass and plastic are relatively easily patched above water, theyare difficult to patch below water. Also, damage to the flange of afiberglass or plastic cover requires a substantial amount of labor torebuild the damaged portion of the flange.

All of the covering and mastic application methods are made moredifficult by the fact that they must sometimes be performed in thewater. Divers are expensive labor and the water environment makes manytasks, which would otherwise be simple, very difficult or impossible.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a flangelesscovering for piles which will conform to the surface irregularities of apile.

It is also an object of the present invention to provide a covering forpiles which will seal the surface of a pile, precluding the entrance ofwater or exposure to the elements.

Another object of the present invention is to provide a plastic coveringfor a pile having an easily joined seam which can be utilized to seal apile after a pile is in place.

It is also an object to provide an improved method for covering a pilewith a plastic protective material such that buckling of the plasticdoes not occur.

It is still further an object of the present invention to provide animproved method of sealing a pile with a plastic cover.

A further object of the present invention is to provide an apparatus andmethod for patching a damaged plastic cover on a pile.

In accordance with these objects, the present invention includes aplastic sheet, having first and second ends. The sheet is adapted toextend around a pile such that the first and second ends overlap. Aheatable strip element is disposed such that when the sheet is wrappedabout a piling with the first and second ends overlapping the heatablestrip is in position for heatably fusing the first and second ends tojoin the sheet in a single, sealed protective covering about the pile.

To use the protective sheet, it is cinched closely about a pile so thatthe ends overlap with the heatable strip extending longitudinally inposition for sealing the sheet. The strip is then heated to form asealing seam. Preferably the heatable strip element is an electricalresistance wire strip and heat is applied by connecting an appropriateelectrical supply to the wire strip. A voltage of approximately 40 Voltsor less of direct current is preferred for safety reasons.

The present invention also provides a method for cinching such a sheetabout a pile. A sheet of the type described above is loosely extendedabout a pile such that the first end overlaps the second end. A bar isplaced on top of the first end. The bar is placed directly over theheatable strip element to provide good contact for forming a sealingseam. Pins in the bar engage openings in the first end of the plasticsheet to capture the first end of the plastic sheet. A strap is attachedto the bar and encircles the pile and sheet. A ratchet means is used towind up the slack existing in the strap such that the bar is rotatedtoward the ratchet means drawing the first end over the second end andcinching the plastic sheet tightly around the pile without buckling. Theheatable strip element is then heated to fuse the plastic along thefirst and second ends at the heatable strip and to seal the plasticsheet about the pile.

A damaged plastic pile cover can be repaired by utilizing a plasticpatch of the present invention. The patch comprises a patch sheet with aheatable strip element which is disposed around the perimeter of thepatch sheet. To use the patch sheet it is tightly pressed over thedamaged area of a plastic pile covering and the heatable strip elementheated to fuse the patch sheet to the plastic pile covering.

Other and further objects, features and advantages of the presentinvention will be readily apparent to those skilled in the art when thefollowing description of the preferred embodiments is read inconjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded plan view of the instant invention disposed arounda wooden pile.

FIG. 2 is an exploded sectional view of a portion of the device shown inFIG. 1.

FIG. 3 is a partial elevation view of a bar of the present inventionshown in FIG. 1.

FIG. 4 is a flattened elevation view of a plastic sheet of the presentinvention shown in FIG. 1.

FIG. 5 is a cross sectional view of a portion of an alternate embodimentof a plastic sheet constructed in accordance with the present invention.

FIG. 6 is a rear elevational view of a plastic patch constructed inaccordance with the invention.

FIG. 7 is an enlarged partial rear elevational view of the patch of FIG.6.

DESCRIPTION OF PREFERRED EMBODIMENTS

Referring now to FIG. 1 the fusible plastic pile protector and cinchingdevice of the present invention is shown generally at 12 in an explodedrelationship around a wooden pile 15 to be covered. The pile protectorof the present invention includes a plastic sheet 14 and the cinchingdevice includes a channel bar 16, a strap 18, and a ratchet 20 attachedto the strap 18. An electrical resistance heating strip 24 is disposedlongitudinally along a vertically extending end 11 of sheet 14. It isconnected to or disposed in an inwardly facing surface 26 of the plasticsheet 14. A surface 28 of the plastic sheet 14 faces outwardly from thepile 10 when the plastic sheet 14 is coiled around the pile 10. Oppositevertically extending end 11 is a vertically extending end 13. The end 11overlaps end 13 so that the heating strip 24 is disposed therebetweenwhen the sheet 14 is ready to be sealed with a vertical seam by heatingthe strip 24. The preferred material for the plastic sheet 14 of thepresent invention is polyethylene. This material possesses excellentflexibility as well as the ability to conform to a surface's contoursand irregularities when stretched across that surface. It also has theproper melt characteristics allowing a good seal seam to be formed whenthe electrical resistance heating strip is heated while the plasticsheet is overlapped and pressed together.

Flexibility is especially important for wooden piles which often taperfrom top to bottom and, in addition, have many surface irregularities.For example, knots of wooden piles often slightly protrude from theconvex surface thereof. Wooden, concrete and metal piles have surfaceirregularities after abrasion and various destructive forces haveattacked the pile during use. Polyethylene is capable of conforming tomost irregularities present in a pile as well as closely sealing anysurface imperfections present therein.

The wrap of the sheet 14 together with the stretch of the polyethyleneallows the sheet 14 to conform to even sharply tapered piles without thenecessity of a custom designed sheet.

Referring to FIGS. 1-4, the plastic sheet 14 has a plurality of openings36 adjacent end 11 and facing outwardly. These openings 36 extend inspaced relationship longitudinally on the plastic sheet 14. The openings36 are provided so that the end 11 of sheet 14 can be captured and drawntight during cinching of the sheet 14 about a pile.

Spaced tangentially inwardly from the openings 36 of the plastic sheet14 is a series of parallel vertically extending channels 38. Thesechannels 38 can be fabricated through a molding or extruding processwhen the plastic sheet 14 is manufactured or by machining after theplastic sheet 14 is fabricated. The channels 38 retain a wire 40 woundin series to form the electrical resistance heating strip 24 and extendlongitudinally from top end to bottom end on the inwardly facing surface26 of the plastic sheet 14. Preferably the wire 40 should be tightlyretained when pressfitted into the channels 38.

The channel bar 16 is an elongated generally U-shaped member and ispreferably manufactured of milled, extruded aluminum. The outwardlyextending arms 42 of the channel bar 16 are perforated by axiallyextending slots 30, with the slots being disposed near both the top andbottom end of the channel bar 16. The channel bar 16 is used in cinchingthe plastic sheet 14 about a pile 15 and in pressing the overlapped ends11 and 13 together during the formation of a longitudinal seam. Theslots 30 are for connecting the strap 18 to the channel bar 16.

The channel bar 16 has a pad 32 affixed to the surface facing theplastic sheet 14 and extends along the entire length of the channel bar16. The pad 32 is preferably elastomeric so as to resiliently press theoverlapped ends 11 and 13 of the sheet 14 together preventing any gapsdespite surface irregularities in the pile 15. The pad 32 can be made ofneoprene rubber.

A plurality of pins 34, for engaging the openings 36 in the plasticsheet 14 extend through the pad 32 and are fixedly connected to thechannel bar 16. The pins 34 are axially spaced along the length of thechannel bar 16 such that the pins 34 will engage and mate with theopenings 36 in the plastic sheet 14. This allows the bar 16 to capturethe end 11 of the sheet 14.

The electrical resistance heating strip 24 is comprised of a single wire40 disposed in the parallel channels 38 of the plastic sheet 14. Thesingle wire 40 comprising the electrical resistance heating strip 24 hasinsulation 41 of polyethylene, also the material of which the plasticsheet 14 is composed. This provides a good sealing seam to form uponheating.

With respect to most polyethylene sheets and other plastic sheets it isdesirable to buff the surface where melting and flowing are to occur.This removes surface materials and promotes a better seam when melted.

The single wire 40 of the electrical resistance heating strip 24 islooped in a sinusoidal pattern through the channels 38 such that thepair of ends 44 thereof exit the plastic sheet 14 in parallel spacedrelation. The number of loops determines the width of the strip. Whenthe plastic sheet 14 is coiled about a pile 15 the strip 24 will beinterposed between the overlapping inner surface 26 and outer surface28. The areas of melt should be prepared by buffing.

Connection of the leads 44 to an appropriate current supply will produceheat to melt and flow of the plastic sheet 14 and the plastic wireinsulation 41 thereby connecting the plastic sheet 14 around the pile15. A sealing seam is formed at the strip location.

In some applications it is desirable to have more than one heatablestrip. Obviously, two or three parallel heatable strips will provide astronger seal and seam connection than one.

The plastic sheet 14 is held tightly in place during heating of theelectrical resistance heating strip 24 by strap 18. Strap 18 includes afirst hook 26 and a second hook 29 for attaching the strap 18 to thechannel bar 16 at the slots 30. The strap 18 encircles the pile 15 andthe plastic sheet 14 loosely coiled thereabout.

The strap 18 has attached to it a ratchet 20 for collecting the strapand reducing the circumference of the strap 18 as it encircles the pile15 and the plastic sheet 14. The ratchet has a hand lever 43 for handoperation of the ratchet and a mechanism for allowing the strap to bereleased or the ratchet reversed. The ratchet 20 should be located nearthe channel bar 16 on the side of the sheet which is under theoverlapped end to help prevent buckling of the sheet 14.

In use, the plastic sheet 14 is coiled around the pile 15 such that theend 13 is overlapped by the end 11. The coiling can be performed by handor the sheet 14 can be precoiled so that it will be retained by its ownresiliency. It should be noted that in order to completely protect thepile 15 the plastic sheet should extend from the top of the pile to thesea floor or below. By trimming the plastic sheet 14, prior to or duringinstallation, to conform to the length of the pile, a standard sizedsheet can be used. It is important to remember that the wire 40 of theheatable strip 24, which is closely fitted into the channels 38 of theplastic strip 14 must be removed prior to trimming the plastic strip 14and reinserted in the channels 38 upon completion of the trimming.

It should also be noted that it is sometimes desirable to prepare thepiling surface to be covered prior to covering. Such preparation caninclude mastics and wraps and paints as are well known to the prior art.One significant advantage of this invention, however, is that thecovering is so tight and sufficiently sealed that less or even nopreparation may be required to achieve the protection provided by otherprocesses and covering devices utilized in the past.

Once the plastic sheet 14 is wrapped around the pile 15, the electricalresistance heating strip 24 will be disposed between the overlappedends. The openings 36 will be facing outwardly on the overlapped end 11.With the sheet wrapped about the pile 15, the pins 34 of the channel bar16 should be aligned with and inserted into openings 36. The pad 32 ofthe channel bar 16 thereby covers the overlapped portion at theelectrical resistance heating strip 24. The first hook 26 and secondhook 29 of the strap 18 are hooked in opposing slots 30 of the channelbar 16.

In most uses the bar 16 will have at least two sets of opposing slots 30and at least two (top and bottom) straps will be used. This providesgood pressure and cinching all along the sheet 14.

In some applications the pins 34 and the openings 36 are unnecessary toobtain tight cinching without buckling. The plastic thickness and thesize of the pile are relevant to this determination.

The strap 18, when hooked to the channel bar 16, encircles the pile 15and the loosely wrapped sheet 14. The hand ratchet mechanism 20,attached to the strap 18, is operated to reel in the strap 18, therebypulling second hook 29 toward (counterclockwise in FIG. 1) ratchet 20.This motion of the hook 29 causes the channel bar 16 to which hook 29 isattached to move the overlapped end 11 over the end 13. In this manner,the end 11 slides over the end 13 until the plastic sheet 14 is tightlycinched around the pile 15.

The second end 13 of the plastic sheet 14 is tapered on its outersurface for facilitating the sliding motion of said first end 11 thereonduring tightening of the plastic sheet 14. This taper also prevents agap from being formed at the overlap.

The method of tightening described above gradually cinches the plasticsheet 14 around the pile 15 without buckling the plastic sheet 14.Because the amount of overlap can vary from pile to pile andlongitudinally along a single pile, this method and device enables theinstallation of a standard size of plastic sheet on piles of variouslengths and diameters and single piles of varying diameter.

Once the plastic sheet 14 is tightly in place on the pile 15, it isfixed in place by fusing the overlapped end 11 and 13. This is achievedby attaching the leads 44 of the wire 40 to an electrical power source.The resistance of the wire 40 to the electrical current causes the wireto heat to a temperature sufficient to melt and flow the insulation andthe plastic sheet 14 forming a bridging and sealing seam between theoverlapped ends of the sheet 14.

After the seam is formed, the power source is disconnected and the seamis allowed to cool and harden. The straps 18 are then removed.

If desired, caulk can be added to the top and bottom ends of the sheet14 to help seal the pile 15. Also, if desired, caulk can be applied tofurther seal the bridging seam formed. In some instances, however,neither of these will be required because of the tight fit of the sheetand the integrity of the bridging seam.

The wire 40 of which the heatable strip 24 is formed, is preferablycomprised of a wire having a uniform resistance per unit of linealmeasure. Current flow against the resistance of the wire 40 sufficientto locally melt the plastic insulation of the wire 40 and the plasticsheet 14, particularly in the area of the channels 38, can be calculatedaccording to the length of wire used and the power source used.Preferably the power source is 40 volts direct current or less to reducethe danger of injurous shock to personnel in the water environment.

Referring now to FIG. 5, an alternative embodiment of the sheet 14 andstrip 24 is shown. In many instances this embodiment is preferred forits ease of manufacture and superiority of bridging seam. In thisembodiment the overlapping end of a plastic sheet 46 is provided with aprotruding electrical resistance heating strip 48. To fix the strip 48on the sheet 46, a wire 49 with a polyethylene insulation is seriallywound inside a wooden mold channel (not shown). This wire and mold arethen properly positioned and pressed against the plastic sheet 46 andcurrent is flowed through the wire 49 to fuse the wire to itself and tothe sheet 46. The ends of the wire 49 are left protruding as in thefirst described embodiment.

If desired this fixation of the strip 48 to the sheet 46 can be done atthe site of installation after trimming of a sheet 46 to size. The holes47 can, if desired be drilled in the field to mate with pins in a barsuch as bar 16. Or, as described above, the pins and holes can beomitted.

Referring now to FIGS. 6 and 7, the present invention includes includesan apparatus and method for patching a plastic cover on a pile. Thepatch of the instant invention is comprised of a plastic material,preferably the same material as the material to be patched, e.g.polyethylene. The patch has an inner or sealing surface 54 in which aheatable strip 52 is embedded or affixed. The heatable strip element 52is a single wire wound serially. The method of embedding or affixing thewire is the same as the embodiment described above. The heatable strip52 tracks the perimeter of the patch in parallel spaced relation. Theleads 56 of the heatable strip exit the patch in parallel spacedrelation.

The patch of the instant invention is easy to install through use of thefollowing method. First, the patch is placed with its inner surface 54in contact with the pile cover over the damaged area to be repaired. Thepatch should be placed over the damaged area such that the heatablestrip 52 thereof completely surrounds the damaged area of a pile cover.Once the patch is properly placed, a bar and strap can be used to applysufficient pressure to provide a good seal upon applying current to meltand flow the plastic around the heatable strip. The bar, of course,would be sized and shaped to fit the patch. The bar and strap can beremoved after the bridging seam has cooled.

Although a wide range of parameters can accomodate the concepts of thisinvention, a typical plastic sheet or patch would be 0.5 centimetersthick, 200 centimeters wide, and 250 centimeters high. The wire for theheating strip would typically be 60 alloy copper wire with a 1 mm coreand a length of 12 meters. Fusion time would typically be 3 to 10minutes. The strip width would typically be 1 to 2 inches. The melt andflow temperatures for most plastics are in the range of 350° F. to 600°F.

The present invention incorporates features which render it inherentlyadvantageous in construction and use over the prior art. For example,use of a plastic sheet instead of a flanged, split-sleeve cover greatlyincreases efficiency in the field in that a single size of plastic sheetis adaptable to various pile-lengths and diameters. In addition, the useof a plastic sheet which is tightened around a pile and remains so,reduces or eliminates the need present in the prior art to coat the pileto be covered with a mastic and to spirally wrap the same with heavypaper to provide an effective seal for a pile surface. The channel bar16, strap 18, and ratchet 20 provides structure well suited to tighten aplastic sheet around a pile such that minor imperfections andirregularities of the pile are sealed.

Another important feature of the instant invention is the means by whichthe plastic sheet 14 is permanently sealed around the pile 15. Asdisclosed above a heatable strip, when heated, forms a strong andsealing bond between the overlapping ends of the sheet. The method ofinstallation is fast and simple.

Another feature of the instant invention is the ability to patch damagedplastic covers for piles. The zippers, flanges, and spike fastening ofthe prior art are, in many instances, incapable of fastening a plasticpatch over a damaged portion of the plastic pile cover. The presentinvention provides a clean patch and a good seal and is easily applied.

Thus, the methods and apparatus of the present invention are well suitedto achieve the objects and advantages mentioned as well as thoseinherent therein. While presently preferred embodiments of the inventionhave been described for the purpose of this disclosure, numerous changesin the construction and arrangement of parts and the steps of themethods can be made by those skilled in the art, which changes areencompassed within the spirit of this invention as defined by theappended claims.

The foregoing disclosure and the showings made in the drawings aremerely illustrative of the principles of this invention and are not tobe interpreted in a limiting sense.

What is claimed is:
 1. A method of covering a pile with a plasticmaterial comprising:extending a plastic sheet having first and secondends around a pile such that said first end overlaps said second end anda strip heatable by electrical resistance heating extends therebetween;sliding said first end over said second end until said plastic sheet istightly cinched around said pile; and, after said extending and slidingsteps applying an electric current to said heatable strip so as to fuseand seal by electrical resistance said first end to said second endforming a fused, tightly wrapped pile cover.
 2. The method of claim 1wherein said sliding step comprises:connecting a bar to said first endof said plastic sheet so as to retain said end as said bar is moved andso as to reside over said heatable strip between said first and secondends; connecting a tightenable strap to said bar about said pile andsheet; and tightening said strap so as to pull said first end of saidsheet over said second end of said sheet and so as to urge said bar topress said heatable strip between said first and second ends.